Summary

This trial will evaluate the safety and efficacy of post-transplant Cy and sirolimus following reduced intensity allogeneic SCT. It is hoped that the combination of a reduced intensity preparative regimen with a calcineurin-free GVHD prophylaxis regimen will decrease the risk of acute and chronic GVHD, by both limiting mucosal toxicity and augmenting immune reconstitution, thereby improving the safety of the procedure. The past experience with post-transplant Cy suggests that SCT recipients will attain rapid donor T cell chimerism, which the investigators hope will translate into improved disease control through the well documented graft-versus-malignancy effects of donor T cells.